Bootstrap 4 Buttons integration

Bootstrap 4 Buttons integration

Looking at the example:https://datatables.net/extensions/buttons/examples/styling/bootstrap4
I see that <button class="btn btn-secondary" has been adopted generally for "top-level" buttons, but <a class="dt-button dropdown-item" is applied for "buttons" in a collection.
Is this styling likely to persist, or is further buttons integration anywhere on the horizon?